Q. I. Rahman [1]} (see also Rahman and Schmeisser [2]}) introduced a class \(\mathcal {B}_n\)  of operators \(B\)  that carries a polynomial \(P\in {P}_n\)  into
\(B[P](z)=\lambda _0P(z)+\lambda _1\left(\dfrac{nz}{2}\right)\dfrac{P^{\prime }(z)}{1!}+\lambda _2\left(\dfrac{nz}{2}\right)^2\dfrac{P^{\prime \prime }(z)}{2!},\) 
